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<html lang="en">
	<head>
		<title>three.js webgl - materials - manual mipmaping</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
		<style>

			.lbl { color:#fff; font-size:16px; font-weight:bold; position: absolute; bottom:0px; z-index:100; text-shadow:#000 1px 1px 1px; background-color:rgba(0,0,0,0.85); padding:1em }
			#lbl_left { text-align:left; left:0px }
			#lbl_right { text-align:left; right:0px }

			.g { color:#aaa }
			.c { color:#fa0 }

		</style>
	</head>

	<body>
		<div id="info">
			<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - texture manual mipmapping example<br/>
			painting by <a href="http://en.wikipedia.org/wiki/Basket_of_Fruit_%28Caravaggio%29">Caravaggio</a>
		</div>

		<div id="lbl_left" class="lbl">
		Floor <span class="g">(128x128)</span><br/>
		mag: <span class="c">Linear</span><br/>
		min: <span class="c">LinearMipmapLinear</span><br/>
		<br/>
		Painting <span class="g">(748x600)</span><br/>
		mag: <span class="c">Linear</span><br/>
		min: <span class="c">Linear</span>
		</div>

		<div id="lbl_right" class="lbl">
		Floor <br/>
		mag: <span class="c">Nearest</span><br/>
		min: <span class="c">NearestMipmapNearestFilter</span><br/>
		<br/>
		Painting <br/>
		mag: <span class="c">Nearest</span><br/>
		min: <span class="c">Nearest</span>
		</div>

		<script type="module">

			import * as THREE from '../build/three.module.js';

			const SCREEN_WIDTH = window.innerWidth;
			const SCREEN_HEIGHT = window.innerHeight;

			let container;

			let camera, scene1, scene2, renderer;

			let mouseX = 0, mouseY = 0;

			const windowHalfX = window.innerWidth / 2;
			const windowHalfY = window.innerHeight / 2;

			init();
			animate();


			function init() {

				container = document.createElement( 'div' );
				document.body.appendChild( container );

				camera = new THREE.PerspectiveCamera( 35, SCREEN_WIDTH / SCREEN_HEIGHT, 1, 5000 );
				camera.position.z = 1500;

				scene1 = new THREE.Scene();
				scene1.background = new THREE.Color( 0x000000 );
				scene1.fog = new THREE.Fog( 0x000000, 1500, 4000 );

				scene2 = new THREE.Scene();
				scene2.background = new THREE.Color( 0x000000 );
				scene2.fog = new THREE.Fog( 0x000000, 1500, 4000 );

				// GROUND

				function mipmap( size, color ) {

					const imageCanvas = document.createElement( "canvas" );
					const context = imageCanvas.getContext( "2d" );

					imageCanvas.width = imageCanvas.height = size;

					context.fillStyle = "#444";
					context.fillRect( 0, 0, size, size );

					context.fillStyle = color;
					context.fillRect( 0, 0, size / 2, size / 2 );
					context.fillRect( size / 2, size / 2, size / 2, size / 2 );
					return imageCanvas;

				}

				const canvas = mipmap( 128, '#f00' );
				const textureCanvas1 = new THREE.CanvasTexture( canvas );
				textureCanvas1.mipmaps[ 0 ] = canvas;
				textureCanvas1.mipmaps[ 1 ] = mipmap( 64, '#0f0' );
				textureCanvas1.mipmaps[ 2 ] = mipmap( 32, '#00f' );
				textureCanvas1.mipmaps[ 3 ] = mipmap( 16, '#400' );
				textureCanvas1.mipmaps[ 4 ] = mipmap( 8, '#040' );
				textureCanvas1.mipmaps[ 5 ] = mipmap( 4, '#004' );
				textureCanvas1.mipmaps[ 6 ] = mipmap( 2, '#044' );
				textureCanvas1.mipmaps[ 7 ] = mipmap( 1, '#404' );
				textureCanvas1.repeat.set( 1000, 1000 );
				textureCanvas1.wrapS = THREE.RepeatWrapping;
				textureCanvas1.wrapT = THREE.RepeatWrapping;

				const textureCanvas2 = textureCanvas1.clone();
				textureCanvas2.magFilter = THREE.NearestFilter;
				textureCanvas2.minFilter = THREE.NearestMipmapNearestFilter;

				const materialCanvas1 = new THREE.MeshBasicMaterial( { map: textureCanvas1 } );
				const materialCanvas2 = new THREE.MeshBasicMaterial( { color: 0xffccaa, map: textureCanvas2 } );

				const geometry = new THREE.PlaneGeometry( 100, 100 );

				const meshCanvas1 = new THREE.Mesh( geometry, materialCanvas1 );
				meshCanvas1.rotation.x = - Math.PI / 2;
				meshCanvas1.scale.set( 1000, 1000, 1000 );

				const meshCanvas2 = new THREE.Mesh( geometry, materialCanvas2 );
				meshCanvas2.rotation.x = - Math.PI / 2;
				meshCanvas2.scale.set( 1000, 1000, 1000 );


				// PAINTING

				const callbackPainting = function () {

					const image = texturePainting1.image;

					texturePainting2.image = image;
					texturePainting2.needsUpdate = true;

					scene1.add( meshCanvas1 );
					scene2.add( meshCanvas2 );

					const geometry = new THREE.PlaneGeometry( 100, 100 );
					const mesh1 = new THREE.Mesh( geometry, materialPainting1 );
					const mesh2 = new THREE.Mesh( geometry, materialPainting2 );

					addPainting( scene1, mesh1 );
					addPainting( scene2, mesh2 );

					function addPainting( zscene, zmesh ) {

						zmesh.scale.x = image.width / 100;
						zmesh.scale.y = image.height / 100;

						zscene.add( zmesh );

						const meshFrame = new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { color: 0x000000 } ) );
						meshFrame.position.z = - 10.0;
						meshFrame.scale.x = 1.1 * image.width / 100;
						meshFrame.scale.y = 1.1 * image.height / 100;
						zscene.add( meshFrame );

						const meshShadow = new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { color: 0x000000, opacity: 0.75, transparent: true } ) );
						meshShadow.position.y = - 1.1 * image.height / 2;
						meshShadow.position.z = - 1.1 * image.height / 2;
						meshShadow.rotation.x = - Math.PI / 2;
						meshShadow.scale.x = 1.1 * image.width / 100;
						meshShadow.scale.y = 1.1 * image.height / 100;
						zscene.add( meshShadow );

						const floorHeight = - 1.117 * image.height / 2;
						meshCanvas1.position.y = meshCanvas2.position.y = floorHeight;

					}


				};

				const texturePainting1 = new THREE.TextureLoader().load( "textures/758px-Canestra_di_frutta_(Caravaggio).jpg", callbackPainting );
				const texturePainting2 = new THREE.Texture();
				const materialPainting1 = new THREE.MeshBasicMaterial( { color: 0xffffff, map: texturePainting1 } );
				const materialPainting2 = new THREE.MeshBasicMaterial( { color: 0xffccaa, map: texturePainting2 } );

				texturePainting2.minFilter = texturePainting2.magFilter = THREE.NearestFilter;
				texturePainting1.minFilter = texturePainting1.magFilter = THREE.LinearFilter;
				texturePainting1.mapping = THREE.UVMapping;

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
				renderer.autoClear = false;

				renderer.domElement.style.position = "relative";
				container.appendChild( renderer.domElement );

				document.addEventListener( 'mousemove', onDocumentMouseMove );

			}


			function onDocumentMouseMove( event ) {

				mouseX = ( event.clientX - windowHalfX );
				mouseY = ( event.clientY - windowHalfY );

			}


			function animate() {

				requestAnimationFrame( animate );

				render();

			}

			function render() {

				camera.position.x += ( mouseX - camera.position.x ) * .05;
				camera.position.y += ( - ( mouseY - 200 ) - camera.position.y ) * .05;

				camera.lookAt( scene1.position );

				renderer.clear();
				renderer.setScissorTest( true );

				renderer.setScissor( 0, 0, SCREEN_WIDTH / 2 - 2, SCREEN_HEIGHT );
				renderer.render( scene1, camera );

				renderer.setScissor( SCREEN_WIDTH / 2, 0, SCREEN_WIDTH / 2 - 2, SCREEN_HEIGHT );
				renderer.render( scene2, camera );

				renderer.setScissorTest( false );

			}

		</script>

	</body>
</html>
